(3033) Proposal to conserve the name Stellaria graminea (Caryophyllaceae) with a conserved type

(3033) Stellaria graminea L., Sp. Pl.: 422. 1 Mai 1753 [Angiosp.: Caryophyll.], nom. cons. prop. Typus: Herb. Burser XI: 111 (UPS No. V-174074), typ. cons. prop. Stellaria graminea L. (Caryophyllaceae) is a perennial and predominantly autogamous herb that often spreads clonally and occupies open, native or man-made habitats from sea level to mountainous zones in Eurasia. It also non-indigenously occurs in North America and New Zealand (e.g., Horne in New. Phytol. 8: 42–73. 1914; Chater & Heywood in Tutin & al., Fl. Europ. 1: 135. 1964; Kurtto in Jonsell, Fl. Nordica 2: 83–84. 2001; Morton in FNA Ed. Comm., Fl. N. Amer. N. Mexico 5: 96–114. 2005). This plant represents a diploid-tetraploid species complex (2n = 2x = 26 and 2n = 4x = 52), the triploid cytotype (2n = 3x = 39) has also been reported (Gadella in Proc. Kon. Ned. Akad. Wetensch. C 80: 161–170. 1977; Harmaja in Ann. Bot. Fenn. 29: 325–327. 1992; Goldblatt & Lowry in Ann. Missouri Bot. Gard. 98: 226–227. 2011; Rice & al. in New Phytol. 206: 19–26. 2015). Stellaria graminea appears to be a good model for understanding the association between sexual polymorphism and whole genome duplication (WGD) and its impact on reproduction evolution (Kučera & al. in Frontiers Pl. Sci. (Online journal) 12: 589093. 2021). WGD is a mechanism playing one of the most remarkable roles in vascular plant evolution (Ramsey & Schemske in Annual Rev. Ecol. Syst. 29: 467–501. 1998; Miller & Venable in Science 289: 2355–2338. 2000; Ashman & al. in Cytogenet. Genome Res. 140: 241–255. 2013; Glick & al. in Amer. J. Bot. 103: 1223–1235. 2016). Linnaeus's protologue of Stellaria graminea (Sp. Pl.: 422. 1753) consists of a short diagnosis "STELLARIA foliis linearibus integerrimis, floribus paniculatis", followed by five synonyms: (1) "Alsine foliis linearibus" taken directly from Linnaeus (Fl. Lapp.: no. 189 [p. 149]. 1737; Fl. Suec.: no. 372 [p. 135]. 1745, and Hort. Cliff.: 172. 1738) and Van Royen (Fl. Leyd. Prodr.: 449. 1740); (2) "Caryophyllus arvensis glaber, flore minore" cited from Bauhin (Pinax: 210. 1623); (3) "Gramen floridum minus" cited from Tabernaemontanus (Eic. Pl. Stirp.: 232. 1590); (4) "Alsine, folio gramineo angustiore, palustris" cited from Dillenius (Cat. Pl. Circa Gissam [App.]: 69. 1719) and marked with the symbol "β"; and (5) "Cariophyllus holosteus alpinus angustifolius" cited from Bauhin (Prodr.: 104 n. 6. 1620; Pinax: 210. 1623) marked with the symbol "γ" and the annotation "Burs. XI: 2". The symbols "β" and "γ" indicate that the protologue includes two unnamed varieties, β and γ. Finally, the provenance is reported in the protologue as "Habitat in siccis juniperetis sepibus tectis Europae." Jonsell & Jarvis (in Nordic J. Bot. 14: 159. 1994) designated as the "lectotype" the specimen Burser Herbarium XI: 111 (UPS), and this "lectotypification" was supported by Jarvis (Order out of Chaos: 874. 2007). However, this "lectotypification" is ineffective because a syntype is cited in the protologue. Linnaeus (l.c. 1753) explicitly cited "Burs. XI: 2". However, unfortunately, the specimen from the Burser Herbarium included in the protologue (as Burs. XI: 2) under the unnamed variety "γ" was miscited by Linnaeus (see Juel in Nova Acta Regiae Soc. Sci. Upsal., ser. 4, 5(7): 75. 1923; in Symb. Bot. Upsal. 2(1). 1936; Jonsell & Jarvis, l.c.). The sheet XI: 2 bears a plant that belongs to a species of the genus Viola, so that must be a mistake in Species plantarum. However, the polynomial cited by Linnaeus in the protologue "Cariophyllus holosteus alpinus angustifolius" taken from Bauhin (l.c. 1620: 104; l.c. 1623: 210) is identifiable with an actual specimen from Joachim Burser's Hortus Siccus XI: 116, currently preserved at UPS-BURSER. Perhaps, Linnaeus's "mistake" is due to the fact that the sheet XI: 116 is annotated "II" at the top of the label. Therefore, the "lectotypification" of Jonsell & Jarvis (l.c.) is unacceptable because Burser's specimen XI: 116, having been cited by Linnaeus (although erroneously as "Burs. XI: 2"), is a syntype (according to ICN Art. 9.6 of the Shenzhen Code, Turland & al. in Regnum Veg. 159. 2018) and has precedence in lectotype designation over the uncited specimens and cited illustrations that comprise the remaining original material of the name (Art. 9.12). Being the sole syntype, it would therefore be the obligate choice for a lectotype (Art. 9.12). The sheet Herb. Burser XI: 116 (UPS No. V-174079) bears a specimen, several stems with leaves and flowers, and a handwritten label annotated as "II | Caryophyllus holosteus alpinus an | gustifolius Bauh. | Habebat florem carnei coloris | In Pyrenaeis Hispaniam versus. | 116". At the bottom of the label it is written, probably by Linnaeus: "pist. 3". Juel (l.c. 1923; l.c. 1936) identified the specimen Herb. Burser XI: 116 as belonging to Arenaria purpurascens Ramond ex DC. (Fl. Franç., ed. 3, 4: 785. 1805) from the Pyrenees. My identification of this material agrees with Juel's identification (e.g., diffuse stems, ascending, glabrous with distinct scale-leaves towards base; puberulent with deflexed hairs, branched and leafy in upper part; leaves 5–10 mm, elliptic-lanceolate or lanceolate, acute, strongly 1-veined, glabrous, ciliate at base; flowers 2–4 in rather dense clusters; pedicels equalling sepals, pubescent, erect in fruit; sepals 4.5–6.5 mm, lanceolate, acute, 3- to 5-veined, glabrous; petals 1.5–2 times as long as sepals, oblong). Therefore, to apply Art. 9.12 would be nomenclaturally disruptive, and a lectotypification of the name Stellaria graminea using the Burser specimen XI: 116 would be undesirable in terms of nomenclatural stability. Accordingly, to support the continued and well-established use of the name S. graminea, I propose to conserve the name with a conserved type under Art. 14.9. I here propose the well-preserved and complete specimen at UPS-BURSER, Herb. Burser XI: 111 (UPS No. V-174074), as the conserved type of Stellaria graminea. This specimen is made up of two plants, with leaves, flowers, and fruits, and is accompanied by a label, annotated as "Caryophyllus arvensis glaber | flore minore Bauh. | Gramen floridum minus Tab. | In Britania, Lusitania, Bohemia", two polynomials cited by Linnaeus in the protologue, from Bauhin (l.c. 1623: 210) and Tabernaemontanus (l.c. 1590: 232), respectively. The specimen shows diagnostic characters of this species (e.g., ascending stems, weak, diffuse, much-branched, quadrangular, smooth; leaves up to 5 cm, linear to elliptic-lanceolate, acute, smooth; inflorescence lax, bracts scarious, ciliate; sepals 3–7 mm, ciliate, pubescent beneath but only near base, glabrous in upper half), and clearly represents the current application of the name (e.g., Horne, l.c.; Chater & Heywood, l.c.; Romo in Castroviejo & al., Fl. Iberica 2: 259. 1990; Kurtto, l.c.; Morton, l.c.). Rejection of the present proposal would have a very undesirable consequence because the universally used name Stellaria graminea could not continue to be used for the Eurasian species described above, since with the only possible lectotypification the name would become an earlier heterotypic synonym of Arenaria purpurascens. Because the heterotypic A. graminea C.A. Mey. (Verz. Pfl. Casp. Meer.: 220. 1831) already exists in Arenaria, there is no risk of displacing the use of A. purpurascens for the species involved, as long as it is retained in that genus. On the other hand, the species currently known as Stellaria graminea would require a new name, and the earliest available name may be difficult to determine for such a wide-ranging species, although Marhold (Euro+Med Plantbase [http://ww2.bgbm.org/EuroPlusMed/PTaxonDetail.asp?NameCache=Stellaria graminea&PTRefFk=7200000], accessed 24 Mar 2024) lists two doubtful synonyms: S. fragilis Klokov (in Novosti Sist. Vyssh. Nizsh. Rast. 1974: 19. 1974) and S. hippoctona (Czern.) Klokov (l.c.: 15, based on S. graminea var. hippoctona Czern.) that would have to be considered. Both S. graminea and A. purpurascens have been in widespread and continuous usage since they were published in 1753 and 1805, respectively. Thanks to Mats Hjertson (UPS) for help in the study of the UPS herbarium sheets. Thanks also to John Wiersema and John McNeill for their advice, assistance, and valuable comments that improved this proposal.